Pattern-Reconfigurable Microstrip Patch Antenna With Multidirectional Beam for WiMAX Application

A parasitic planar patch antenna capable of multi directional pattern reconfiguration is presented. The antenna structure consists of a driven element surrounded by four parasitic elements that act either as reflector(s) or director(s) depending on the switching arrangement. Beam reconfiguration is achieved by using four p-i-n diode switches where the effect of switching technique on the overall element performance is investigated numerically and experimentally. The proposed antenna achieves nine distinguished main beam angular positions. Moreover, the proposed antenna has achieved excellent realized gain levels at all configuration scenarios with a minimum value of 7 dBi. Simulation and measurement results show good agreement and promising applications of such antenna structure in enhanced WiMAX systems.

I. Introduction

Reconfigurable antennas offer flexibility in terms of frequency, pattern, and polarization, hence versatile and flexible operations in many applications. In a rich scattering environment, it is preferred to have an antenna that can direct the main beam to the desired coverage area while suppressing the unwanted beam in other directions. Therefore, multipath propagation fading can be mitigated and eventually improve the spectral efficiency considering that higher rate of information can be transmitted in a given bandwidth [1], [2].